IBM launched a 1GHz G3-class PowerPC processor, the 750FX, yesterday - a couple of days ahead of its scheduled introduction, but who's counting?

Not, we hope, when they could be reading the chip's stats: 512KB on-die L2 cache; silicon-on-insulator, low-k dielectric construction; copper interconnects; 0.13 micron fabrication process; 200MHz frontside bus - not high compared to the x86 world, but big for PowerPC, and capable of offering 25 per cent more bandwidth than previous G3-class processor, IBM claims.

All this in a die that's just 34.6sq mm but packs in 39 million transistors and consumes just 3.6W at 800MHz (it's available in 700MHz-1GHz varieties).

Alas there's no AltiVec-style SIMD (Singe Instruction, Multiple Data) engine, as we mused out loud last week, on the basis of what IBM has noted in its roadmap. We'll have to wait for the 750FX's 1GHz+ successor for this.

How soon will we see the 750FX turn up in iMacs and iBooks? Not for a wee while. IBM will ship samples early next year, but it should make the part available in volume - and hence in Macs for sale - pretty quickly. We'd like to think the first gigahertz iMac launching on the consumer computer's fourth birthday next May. The timing's right, if nothing else.

Whatever iMac developments Apple has in the pipeline, the company will almost certainly want to get a 1GHz Power Mac out first. For all the company's -correct - insistence that a processor's clock speed isn't an absolute measure of performance, it will not want to risk shipping a consumer machine which appears to be faster than its pro systems.

Fortunately, if Apple goes with Motorola's G5 processor or even the third generation of the G4 family, codenamed Apollo, it should be able to release a 1GHz+ Power Mac before announcing an equivalently clocked iMac. ®